Dynamo and magneto-electric machine.



Patented Sept. 9, I902. N. H. EDGERTUN.

DYNAMO AND MAGNET!) ELECTRIC MACHINE.

(Application filed Aug 22, 1901.)

(No Model.)

2 Sheets-Sheet I.

THE mums PETERS co, PnoTouwa, wnsumcnon, n c.

No. 708,803. Patented Sept. 9, I902. w. H. EDGERTON. DYNAMO AND MAGNETD ELECTBIC'MACHINE.

(Application filed Au 22, 1901 2 Sheets Sheet 2.

(No Model.)

Snuenl'oz,

UNITED STATES PATENT OFFICE.

NATHAN HUNTLEY EDGERTON, OF PHILADELPHIA, PENNSYLVANIA.

DYNAMO AND MAGNETO-ELECTRIC IVACHINE.

SPECIFICATION forming part of Letters Patent N 0. 708,803, dated September 9, 1902.

Application filed August 22,1901. Serial No. 72,866. (No model.)

To aZZ whom it may concern:

Be it known that I, NATHAN HUNTLEY ED- GERTON, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Improvement in Dynamo and Magneto-Electric Machines, of which the following is a specification.

My invention relates to improvements in dynamo and magneto-electric machines; and the object of my invention is to construct the field of a magneto-electric machine in such a manner as to prevent, as far as possible, magnetic nodes in the field-magnets and also to control the magnetic density of the field for the purpose of intensifying its inductive action, and, further, to produce motors and dynamos of cheaper construction and simpler mechanism in both the electromagnetic types and magneto-electric types; and it consists especially in the electromagnetic machine in eliminating from the machine the heavy wirewound pole-pieces and cores now used in the ordinary construction of electric machines, and in the magneto-electric machine it consists in so arranging the magnets that the current flowing through the armature intensifies the electric value of the field-magnets. To do this, I place the laminated field of the one machine in such a position that the windings of the armature-circuit cross the laminze of the field at right angles thereto, forming" an electromagnet with two poles in either section of the field, making, as in the ordinary dynamo, a bipolar machine with two north and two south pole terminations of the field. The two north and two south poles are opposite each other, asis usual in the bipolar dynamo. This construction is actually using the windings of the armature to replace the copper-wire windings of the field-magnets in the ordinary type of dynamo, and it is evident on inspection that the magnetization of the laminated field can be held as permanent and the magnetic strength maintained as easily as in the old style of machine, because no matter atwhat speed the armature is running there will be the same number of convolutions acting upon each half of the fieldmagnet as if the armature were standing at rest, and the increase in magnetization can be effected by varying the armature-turns'as in the ordinary dynamo-machine.

1n the construction of the magneto-electric machine the same general arrangement is adopted, so as to obtain from the current generated and flowing through the armature an increase in the magnetic force at the magnetic poles. It makes no difference to this magneto-electric machine whether it is used for a motor'or a dynamo, as the reaction between the armature and the laminated field is thesame, and the fields will build up under the action of the current generated by the laminated field, giving a still higher effect than can be obtained from any other form or manner of disposing the laminated field around the armature; and it consists, essentially, in making the inductive field of any suitable number of magnets made either of steel or soft iron suitably constructed and held in place, as hereinafter more particularly explained. Any armature can be used with my machine, provided the windings of the same are parallel to the armature-shaft, and therefore at right angles to the laminated field. Therefore it will be understood that the windings of the armature shown in the drawings are at right angles to the laminated field. I may use for the laminated field either soft iron, such as Norwegian or Russian iron, or else permanent steel magnets. It will of course be understood that the frame of the machine which incloses the fields is of diamagnetic material, such as aluminium or the like, thereby isolating each field from the other. In each case by revolving the windings of the armature and cutting the flux of the laminated field at right angles by said windings the saidlaminated field reacts from the armature-current, so that the inductive action of the field-magnets is increased. It is well known that there is in soft iron what is known as residualmagnetism but these said magnets are far too weak to be of any use as ordinarily used in work requiring strong magnets. (I am now speaking of electromagnets. I am speaking of soft iron used as I intend to use same without any wire wound around or encircling same.) Now by cutting the flux of said soft-iron magnets in substantially the manner described (this flux is caused by the residual magnetism in said magnets no matter how weak) at right angles by the armature-windings the said softiron magnets react from the armature-current, and thus have their inductive powerincreased. This I claim to be new and patentable.

Figure l is a perspectiveview of the mag neto-electric machine, parts broken away, showing the laminated magnets which form the field thereof. Fig. 2 is a cross-section through the frame of the machine and the laminated magnets, showing the position of the laminte and a manner of securing them in place. Fig. 3 is a View showingthe windings of the armature running parallel with the armature-shaft. Fig. 4 represents a section on line 00 00, Fig. 3.

In the drawings like letters of reference indicate corresponding parts in each figure.

A is the main frame of the machine, made of diamagnetic material, and B and C the end supports of same, said supports being also of diamagnetic material.

D is the armature-shaft, which is supported in suitable bearings, such as E, forming part of the end supports B and O of the machine. One of the bearings E only is shown.

F is the armature, and G the commutator. Although I have not shown the specific construction of the armature used in my machine, it will be understood that I can use any type of armature the windings of which are parallel to the armatureshaft, consequently being at right angles to the laminated field, as will be understood from Figs. 3 and 4.

H represents the brush-holders, and I the brushes. Resting against the inside of the frame A and suitably supported in position by their ends abutting the retaining-bars J (which are secured by screwsj to the main frame A or forming part thereof) are a number of laminated magnets L, made either of Norwegian or Russian soft iron or of steel. These magnets form the field of the machine. The said magnets are semicircular in shape, as shown, and are placed one upon the other, as will be seen from the drawings. It takes three laminze placed side by side to extend the width of the field in the machine shown in the drawings; but it will of course be understood that I can make the said laminae the Whole required width of the field and not depart from the spirit of my invention or use any number of laminae of a desired Width for the field. The laminae placed next the armature F have their ends overlapped by the edges of the plates ff, as shown, which are secured to or form part of the piece of diamagnetic material, as shown. This construction securely holds the laminae in place and also permits of their speedy removal when necessary. It will of course be understood that the plates ff, secured to or forming part of the pieces of diamagnetic material J, are also made of the same diamagnetic material as the pieces J. I have found that by laminating the field in the manner described I can eliminate the magnetic nodes, which have heretofore lessened the efficiency of permanent magnets to such a degree as to make itimpracticable to use them. It will of course be understood that as the number of laminated magnets is increased in the field the efficiency of the machine is increased.

Referring to Fig. 2 of the drawings it will be conceived that if a line be drawn from A to B the armature will be cut into two equal segments. These segments will at all times,

whether rotating or standing still, have the same number of wires on the side A D B as on the side A C B and these wires so cut or traverse the field-magnets with a current flowing through them,will produce an electromagnetic result in proportion to the amount of current so passed through them or, in other words, to the number of ampere-turns traversing to what is to all intents and purposes the field-circuit, although that circuit revolves with the armature. For instance, if a current flowing through the armature having its entrance at A and its exit at B when ten amperes are flowing has a total result of ten thousand amperes turns it will produce a certain magnetic force at O and at- D. Now if this current of ten amperes be increased to twenty we would have a result of twenty thousand ampere-turns with double the magnetic moment at O and D, and this will always be the same whether the armature is rotating or is held at rest, because though the armature revolves, and no matter how fast it revolves, there is still in each segment of the armature the same number of ampere-turns acting upon the field-magnet, making what is called a dynamo-machine, or an electromagnetic machine if soft-iron laminae are used, and if permanent steel magnets are used a magneto-electric machine, with an inductive field actingthrough the magnets to increase their magnetic moment in addition to the magnetism held permanently by the said magnets. It should also be understood that I do not limit myself to piles or groups oflaminated iron plates or steel plates; but the plates may be cut into circular segments and be placed edgewise in the plane of rotation, or they may be made of rods or wires so grouped about the armature as to be actuated by the current flowing through the armature-coils.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In an electric machine, the combination of an armature, an annular frame, spacing devices secured to the inner periphery thereof at diametrically opposite points and having beveled edges which contact with the ends of the curved magnet-strips, the latter being retained in position by their contact with said spacing devices, said strips being concentric with and within the plane of rotation of the armature.

2. In an electric machine, the combination of an armature, an annular frame, spacing devices secured to the inner periphery of said frame at diametrically opposite points, and having beveled edges which contact with the ends of curved magnet-strips, the latter be ing retained in position by their frictional contact with said spacing devices, said strips being placed in sections concentric With and within the plane of rotation of the armature, so as to form an inductive field.

3. In an electric machine, the combination of an armature, having its windings parallel with its shaft, and an annular frame, of reraining-bars upon the inner faces of said frame upon diametrically opposite sides and having beveled edges, and curved laminated soft-iron magnets forming the field of the machine disposed Within said frame with their ends abut-ting against the beveled edges of said retaining-bars.

4. In an electric machine, the combination of an armature, having its windings parallel with its shaft and an annular frame inclosing said armature, of retaining-bars upon the inner faces of said frame, and having beveled edges, curved laminated soft-iron magnets forming the field of the machine with their ends abuttingagainst the beveled edges of the said bars, and plates of diamagnetic material secured to the inner faces of said bars.

5. In an electric machine, the combination of an armature, having its windings parallel with its shaft, and an annular frame inclosing said armature, of retaining-bars on the inner face of said frame and having beveled edges, curved laminated soft-iron magnets forming the field of the machine disposed within said frame in a plane concentric with the armature and having their ends abutting against said bars, and plates of diamagnetic material secured to the inner face of said bars and overlapping the adjacent ends of said magnets.

NATIIAN HUNTLEY lt'DGER'lON.

Witnesses:

JOHN A. WIEnERsI-IEIM, G. D. M CVAY. 

